Pointing device reporting utilizing scaling

ABSTRACT

A method and a pointing device are provided for reporting a movement amount of an operation instrumentality of the pointing device. A first value representing the movement amount in a first direction is examined. Whether scaling should be performed is determined based on the first value. When it is determined that scaling is to be performed, the first value is scaled by a first scaling factor and a first scaling indicator is set to indicate that the first value is scaled by the first scaling factor. Reporting information is then output, including the first value if scaling has not been performed, and when scaling has been performed, the reporting information includes the scaled first value and the first scaling indicator. The first value may be scaled by one of a plurality of scaling factors selected based on the first value.

FIELD OF THE INVENTION

The present invention relates to pointing devices used with computersand other data input devices, and methods that may be used to report achange in position of an operation instrumentality of the pointingdevice. More specifically, the invention relates to a format forreporting the change in position of an operation instrumentality of apointing device.

BACKGROUND OF THE INVENTION

Known mechanical computer mice have been specified to have a resolutionof 400 dots per inch (dpi) and a maximum speed of 5 inches per second(ips), and may be tested before shipping to 7 ips. Some optical sensorswithin optical computer mice may be specified as having the sameresolution as mechanical computer mice, but are capable of much higherspeeds, such as speeds greater than 50 ips. In prior computer mice (bothmechanical and optical), the resolution and speed limits imply that nomore than 7 bits of magnitude are needed to transmit the number of dots(Δx, Δy) counted during sampling intervals. For example, values from 0through 127 can be represented in a 7 bit value and values in the rangeof −128 through 127 can be represented by a two's-complement value in 8bits (a 7 bit magnitude and a sign bit).

One particular prior art optical wireless computer mouse appears to sendan 8 bit signed value (using a resolution of 800 dpi), indicating anamount of movement in each of a horizontal and vertical direction, via aRadio Frequency (RF) packet every 20 milliseconds. This would yield amaximum mouse speed of about 8 ips. (50 RF packets per second (20millisecond time intervals)×127 (maximum signed 8 bit value)×0.00125inches per dot (800 dpi resolution)=7.9375 inches per second). Using aresolution of 400 dpi would yield a maximum speed of about 16 ips;however, the maximum tracking speed that a low speed USB device cansupport is 36 ips (at a 400 dpi resolution).

A ten-fold increase in speed, as may be attained by an optical mouse,means that the Δx, Δy data could have a magnitude up to ten times largerthan the magnitude for prior art mechanical mice. Therefore, 4additional bits, or 11 bits would be required to report such a magnitudeand 12 bits would be required to report the 11 bit magnitude and a signbit. Since the smallest unit of addressable memory is a byte, anadditional byte of memory would be required to accommodate theadditional bits for reporting such a large magnitude. Given thatavailable memory, such as Random Access Memory (RAM), is limited, ameans for reporting such a large magnitude without using additional bitsto represent the magnitude would be desirable.

SUMMARY OF THE INVENTION

The present invention addresses the above situation by providing apointing device and a method for reporting a movement amount of anoperation instrumentality of a pointing device, such that fewer bits maybe used to report the movement amount of the operation instrumentalitythan when using a conventional reporting method.

In a first aspect of the invention, a method is provided for reporting amovement amount of an operation instrumentality of a pointing device. Afirst value representing the movement amount in a first direction isexamined. A determination is made as to whether scaling of the firstvalue is to be performed based on the first value. When scaling is to beperformed, the first value is scaled by the first scaling factor and afirst scaling indicator is set to indicate that the first value isscaled by the first scaling factor. Reporting information is thenoutput. If no scaling has been performed, the reporting informationincludes the first value. If scaling has been performed, the reportinginformation includes the scaled first value and the first scalingindicator.

In a second aspect of the invention, a pointing device is provided. Thepointing device includes a tracking engine, determining means, a scaler,and a position reporter. The tracking engine is configured to track amovement amount of an operation instrumentality of the pointing devicein a first direction, and to indicate the movement amount as a firstvalue. The determining means is configured to examine the first value todetermine whether scaling of the first value should be performed basedon the first value. The scaler is configured to scale the first value bya first scaling factor when the determining means determines thatscaling is to be performed. The position reporter is configured toreport information including the first value if no scaling has beenperformed, and to report information including the scaled first valueand the first scaling indicator, corresponding to the first scalingfactor, if scaling has been performed.

In a third aspect of the invention, a method is provided for reporting amovement amount of an operation instrumentality of a pointing device. Afirst value representing the movement amount in a first direction isexamined. The first value is checked to determine whether the firstvalue can be represented by a first predetermined number of bits. Whenthe first value cannot be represented by the first predetermined numberof bits, the first value is scaled by a first scaling factor and a firstscaling indicator is set to indicate that the first value is scaled.Reporting information is then output. If no scaling has been performed,the reporting information includes the first value. If scaling has beenperformed, the reporting information includes the scaled first value andthe first scaling indicator.

In a fourth aspect of the invention, a method is provided for reportinga movement amount of an operation instrumentality of a pointing device.A first value representing the movement amount in a first direction isexamined. The first value is checked to determine whether the firstvalue can be represented by a first predetermined number of bits. Whenthe first value can be represented by the first predetermined number ofbits, a first scaling indicator is set to indicate that the first valueis unscaled. When the first value cannot be represented by the firstpredetermined number of bits, the first value is checked to determinewhether the first value can be represented by a second predeterminednumber of bits, which is different from the first predetermined numberof bits. When the first value can be represented by the secondpredetermined number of bits, the first value is scaled by a firstscaling factor and a first scaling indicator is set to indicate that thefirst value is scaled by the first scaling factor. When the first valuecannot be represented by the second predetermined number of bits, thefirst value is checked to determine whether the first value can berepresented by a third predetermined number of bits, which is differentfrom the first and the second predetermined numbers of bits. When thefirst value can be represented by the third predetermined number ofbits, the first value is scaled by a second scaling factor and the firstscaling indicator is set to indicate that the first value is scaled bythe second scaling factor. Reporting information is then output. If noscaling has been performed, the reporting information includes the firstvalue. If scaling has been performed, the reporting information includesthe scaled first value and the first scaling indicator.

In a fifth aspect of the invention, a pointing device is provided. Thepointing device includes a tracking engine, determining means, a scaler,and a position reporter. The tracking engine is configured to track amovement amount of an operation instrumentality of the pointing devicein a first direction, and to indicate the movement amount as a firstvalue. The determining means is configured to determine whether thefirst value can be represented by a first predetermined number of bits.When the determining means determines that the first value can berepresented by the first predetermined number of bits, a first scalingindicator is set to indicate that the first value is unscaled. When thefirst value cannot be represented by the first predetermined number ofbits, the determining means determines whether the first value can berepresented by a second predetermined number of bits, which is differentfrom the first predetermined number of bits. When the first value can berepresented by the second predetermined number of bits, the scaler isconfigured to scale the first value by a first scaling factor and to seta first scaling indicator to indicate that the first value is scaled bythe first scaling factor. When the determining means determines that thefirst value cannot be represented by the second predetermined number ofbits, the determining means determines whether the first value can berepresented by a third predetermined number of bits, which is differentfrom the first and the second predetermined numbers of bits. When thedetermining means determines that the first value can be represented bythe third predetermined number of bits, the scaler is configured toscale the first value by a second scaling factor, and to set the firstscaling indicator to indicate that the first value is scaled by thesecond scaling factor. The position reporter is configured to reportinformation including the first value if no scaling has been performed,and to report information including the scaled first value and the firstscaling indicator, if scaling has been performed.

In a sixth aspect of the invention, a pointing device having a trackingengine, determining means, a scaler and a position reporter is provided.The tracking engine is configured to track a movement amount of anoperation instrumentality of the pointing device in a first direction,and to indicate the movement amount as a first value. The determiningmeans is configured to determine the smallest of a first, second andthird ranges of values into which the first value falls, and to set afirst scaling indicator to indicate scaling by a first selected scalingfactor based on the determined range if the first value falls into oneof the first, the second and the third ranges. A scaler is configured toscale the first value by the first selected scaling factor. The positionreporter is configured to report information including the first valueif no scaling has been performed, and to report information includingthe scaled first value and the first scaling indicator, if scaling hasbeen performed.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is described with respect to the accompanyingfigures, in which like reference numerals identify like elements, and inwhich:

FIG. 1 is a block diagram of a pointing device representing anembodiment of the invention;

FIG. 2 is a functional block diagram of the pointing device illustratedin FIG. 1;

FIG. 3 illustrates an embodiment of the position reporter shown in FIG.2;

FIG. 4 shows a portion of a reporting format of an embodiment of theinvention;

FIGS. 5A and 5B are respective portions of a flowchart illustratingprocessing in an embodiment of the invention; and

FIGS. 6A and 6B are respective portions of a flowchart illustratingprocessing in another embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the block diagram of FIG. 1, a computer pointing device 10includes a tracking engine, which tracks an amount of movement of anoperation instrumentality of (or associated with) a pointing device. Theoperation instrumentality may be, e.g., a mouse body itself or a movablemember thereof such as a ball, a track ball in a track ball device, apen in a pen-based input device or a user's finger along a touch pad orthe like. The tracked amount of movement of the operationinstrumentality of the pointing device is used to determine a positionof a pointer appearing on a display. A processor 14 may periodicallypoll tracking engine 12 to receive values representing a change inposition of the operation instrumentality. The values may represent achange in position of a number of dots, wherein a typical resolution is400 dots per inch (dpi). In this embodiment of the invention, two valuesare reported, XCount, representing a change in position in a horizontaldirection and YCount, representing a change in position in a verticaldirection. Processor 14 may be connected via a bus to computer memory,such as Read Only Memory 16 (ROM) and Random Access Memory 18 (RAM).Processor 14 provides the values representing the change in thehorizontal and the vertical positions to position reporter 20 forreporting.

Referring to the functional block diagram of FIG. 2, tracking engine 12may receive polls from comparator 24 and supplies comparator 24 withvalues representing a change in position of the operationinstrumentality of the pointing device. In this embodiment, the valuesrepresent a change in a horizontal and a vertical direction. Comparator24 examines the values representing an amount of movement in each of thetwo directions and determines whether each of the values can berepresented in a predetermined number of bits. For example, if eightbits are used to represent a signed value in a two's complementrepresentation, the eight bits may represent a value in the range from−128 to +127. If either of the two values, representing a change inmovement in the two directions, respectively, can be represented in aneight bit signed representation, then the values will be provided to aposition reporter 20 for reporting to, for example, a personal computer.If either of the two values cannot be represented by the predeterminednumber of bits, for example, eight bits, for a signed representation,then the respective value will be scaled (e.g., divided) by a scalingfactor, such as, for example, four, and a scaling indicator will be setto indicate that the reported value has been scaled. The values and thescaling factors are then provided to position reporter 20 for reporting.

FIG. 3 shows an implementation of position reporter 20 in an embodimentof the invention. In this embodiment, the pointing device is a wirelesspointing device. The wireless pointing device includes an RF transmitter30 and antenna 32 for transmitting position reports to, for example, apersonal computer having an RF receiver.

FIG. 4 shows a portion of a reporting packet for reporting the change inposition in each of the two directions. RFPacket [X] comprises an eightbit value including bits X0 through X6 and XS and similarly, RFPacket[Y] includes eight bits Y0 through Y6 and YS. Each of these eight bitvalues can represent a two's complement number in a range from −128 to+127. Flags ScalingFlag[X] and ScalingFlag[Y] are flags indicate whetherthe respective values in RFPacket [X] and RFPacket [Y] have been scaled.

Referring now to the flowchart of FIGS. 5A and 5B, a method of anembodiment of the invention is explained. In this embodiment two typesof displacement are reported, the actual displacement and ¼ of theactual displacement. This effectively reduces the exponent field,corresponding to the scaling flag or indicator, to a single bit, whichfurther saves space in the resulting RF packet, while maintainingaccuracy at low to medium mouse speeds. In this embodiment, the pointingdevice accumulates motion displacements from tracking engine 12 into 16bit accumulators. At P500, comparator 24 polls tracking engine 12 forvalues, for example, ΔX and ΔY, representing an amount of movement ofthe operation instrumentality in each of two directions.

At P502, a check is made to determine whether there is any new data toreport. This can be accomplished, for example, by determining whethereither of ΔX or ΔY is non-zero. If ΔX or ΔY is non-zero, then there isnew data to report and the process continues with step P504. Otherwisethe process proceeds to step P500 to poll the tracking engine again.

At P504, comparator 24 accumulates a respective value for each of thetwo reported values into the respective 16 bit accumulators. Forexample, a count, XCount is determined by adding a current value ofXCount to ΔX to provide a new value of XCount and a count, YCount, isdetermined by adding a current value of YCount to ΔY to provide a newvalue of YCount.

P506 is performed to determine whether the value of XCount can berepresented by a predetermined number of bits. In this embodiment,determination is made as to whether the value of XCount can berepresented in an eight bit two's complement value. Thus, it isdetermined whether the value XCount is in a range of −128 to +127. IfXCount is within this range, then at P508, the value of XCount is notscaled, but is placed in a reporting packet and a scaling flag is resetto zero. That is, the unscaled mantissa is reported with an exponent(scaling flag) indicating that the mantissa reflects the actual motiondisplacement.

If at P506, comparator 24 determines that the value of XCount is notwithin the range of −128 through +127, then XCount is divided by ascaling factor, for example, four. That is, XCount is shifted to theright by two bits (causing the least significant two bits to be dropped)and the shifted value of XCount is then placed in a reporting packet.The scaling flag, ScalingFlag[X], is set to one to indicate that thereported XCount value has been scaled. That is, the scaled mantissa(approximately ½ the motion displacement) is reported with an exponent(scaling flag) indicating that the mantissa reflects ¼ of the actualmotion displacement. Some accuracy may be lost (note that the two leastsignificant bits are dropped during the shifting operation), but this isinsignificant when the operation instrumentality of the pointing deviceindicates high-speed motion displacement.

At P512, the comparator 24 determines whether the value of YCount can berepresented by the predetermined number of bits. That is, the comparatordetermines whether −128≦YCount≦127, in this embodiment. If YCount iswithin this range, then YCount is placed in the reporting packet and thescaling flag, ScalingFlag[Y], is reset to zero at P514. That is, theunscaled mantissa is reported with an exponent (scaling flag) indicatingthat the mantissa reflects the actual motion displacement. Otherwise,the value in YCount is shifted to the right by two bits (causing theleast significant two bits to be dropped), or divided by four, andplaced in the reporting packet and the scaling flag, ScalingFlag[Y], setto one to indicate that the value of YCount in the reporting packet isscaled. That is, the scaled mantissa (approximately ¼ the motiondisplacement) is reported with an exponent (scaling flag) indicatingthat the mantissa reflects ¼ of the actual motion displacement.

At P518, the reporting packet is sent to, for example, an RF receiverassociated with a computer, for example, a personal computer.

The following example shows how values of XCount and YCount may bereported in the above embodiment of the invention. For example, supposethat the values to be reported are an XCount value of 345 and a YCountvalue of 46. Because XCount is not within the range of −128 through+127, the value 345 will be shifted to the right by two bits, or dividedby four, which produces the value 86. The scaling flag associated withX, ScalingFlag[X] is then set to one to indicate that the reported valueof XCount has been scaled. As mentioned above, while a loss of precisionmay occur when performing scaling, the loss is generally not significantwhen moving a pointing device at high speed.

In the example, the value for YCount is 46, which is within the range of−128 through +127. Therefore, the value of YCount would be reportedwithout performing scaling and the scaling flag associated with YCount,ScalingFlag[Y], would be reset to zero to indicate that no scaling ofYCount was performed.

Referring now to the flowchart of FIGS. 6A and 6B, a method of anotherembodiment of the invention is explained. This embodiment uses one of 4different exponents with a 6 bit displacement value. One of four scalingfactors, corresponding to one of four exponents, may be selected forscaling the XCount value and the YCount value. The four scaling factorsmay be, for example, 0 through 3, corresponding to exponents 2⁰, 2¹, 2²and 2⁴, respectively.

Steps P600 through P604 correspond to steps P500 through P504,respectively, and therefore, will not be discussed further.

At P606, the value of XCount is examined to determine whether it willfit in a first predetermined number of bits, for example, a six bitsigned two's complement number. That is, XCount is checked to determinewhether it is within a range of −32 to +31. If the value of XCount fallswithin this range, then the value of XCount will be copied into thereporting packet and the scaling flag corresponding to XCount,ScalingFlag[X], will be set to zero indicating no scaling. That is, theunscaled mantissa is reported with a scaling factor of 0, indicating anexponent of 2⁰.

If, at P606, comparator 24 determines that XCount does not fall withinthe range of −32 to +31, then at P610, a check will be made to determinewhether XCount can fit into a second predetermined number of bits. Thatis, whether XCount will fit into a seven bit two's complement number.Therefore, XCount is checked to determine whether it is in a range from−64 through +63. If it is within this range, then at P612, the value ofXCount will be shifted to the right by one bit (dropping the leastsignificant bit), effectively dividing XCount by two and placing theshifted value of XCount in a reporting packet. The scaling flag,ScalingFlax[X] will be set to one indicating that the value of XCounthas been scaled. That is, the scaling flag, corresponding to an exponentof 2 ¹, indicates that the mantissa has been scaled to ½ of its originalvalue.

If, at step P610, the comparator 24 determines that XCount does not fallwithin the range of −64 through +63, at P614, a determination will bemade as to whether XCount can fit within a third predetermined number ofbits. That is, in this embodiment, whether XCount can fit into an eightbit two's complement number. Therefore, XCount is checked to determinewhether it is in a range from −128 to +127. If it is within this range,then P616 will be performed to shift the value of XCount to the right bytwo bit positions (causing the least significant two bits to bedropped), effectively dividing XCount by four and placing the shiftedvalue of XCount in the reporting packet. The scaling factor for XCount,ScalingFactor[X], will be set to two, corresponding to an exponent of2², and indicates that the mantissa has been scaled to ¼ of its originalvalue.

If, at step P614, the comparator 24 determines that XCount does not fallin the range of −128 to +127, then P618 will be performed to shift thevalue of XCount to the right by four bit positions (causing the leastsignificant four bits to be dropped), effectively dividing XCount bysixteen and placing the shifted value of XCount in the reporting packet.The scaling factor for XCount, ScalingFactor[X], will be set to three,corresponding to an exponent of 2⁴, and indicates that the mantissa hasbeen scaled to {fraction (1/16)} of its original value.

At P620, the value of YCount is examined to determine whether it willfit in a first predetermined number of bits, for example, a six bitsigned two's complement number. That is, YCount is checked to determinewhether it is within a range of −32 to +31. If the value of YCount fallswithin this range, then the value of YCount will be copied into thereporting packet and the scaling flag corresponding to YCount,ScalingFlag[Y], will be set to zero indicating no scaling. That is, theunscaled mantissa is reported with a scaling factor of 0, indicating anexponent of 2⁰.

If, at P620, comparator 24 determines that YCount does not fall withinthe range of −32 to +31, then at P624, a check will be made to determinewhether YCount can fit into a second predetermined number of bits. Thatis, whether YCount will fit into a seven bit twos complement number.Therefore, YCount is checked to determine whether it is in a range from−64 through +63. If it is within this range, then at P626, the value ofYCount will be shifted to the right by one bit (dropping the leastsignificant bit), effectively dividing YCount by two and placing theshifted value of YCount in a reporting packet. The scaling flag,ScalingFlag[Y] will be set to one indicating that the value of YCounthas been scaled. That is, the scaling flag corresponds to an exponent of2¹ and indicates that mantissa has been scaled to ½ of its originalvalue.

If, at step P624, the comparator 24 determines that YCount does not fallwithin the range of −64 through +63, at P614, a determination will bemade as to whether YCount can fit within a third predetermined number ofbits. That is, in this embodiment, whether YCount can fit into an eightbit two's complement number. Therefore, YCount is checked to determinewhether it is in a range from −128 to +127. If it is within this range,then P629 will be performed to shift the value of YCount to the right bytwo bit positions (causing the least significant two bits to bedropped), effectively dividing YCount by four and placing the shiftedvalue of YCount in the reporting packet. The scaling factor for YCount,ScalingFactor[Y], will be set to two, corresponding to an exponent of2², and indicates that the mantissa has been scaled to ¼ of its originalvalue.

If, at step P628, the comparator 24 determines that YCount does not fallin the range of −128 to +127, then, at P630 will be performed to shiftthe value of YCount to the right by four bit positions (causing theleast significant four bits to be dropped), effectively dividing YCountby sixteen and placing the shifted value of YCount in the reportingpacket. The scaling factor for YCount, ScalingFactor[Y], will be set tothree, corresponding to an exponent of 2⁴, and indicates that themantissa has been scaled to {fraction (1/16)} of its original value.

At P632, the reporting packet is sent to, for example, an RF receiverassociated with a computer, for example, a personal computer.

The embodiment of FIGS. 5A and 5B may use, for example, 8 bits for thesigned displacement or mantissa and 1 bit for the scaling flag orexponent. The embodiment of FIGS. 6A and 6B may use, for example, 6 bitsfor the signed displacement or mantissa and 2 bits for the scaling flagor exponent. Thus, in the latter embodiment, one fewer bit, 8 bits, maybe used as compared to the former embodiment's use of 9 bits to report achange of position in a direction. Of course, other numbers of bits maybe used for the signed displacement and the scaling flag. Theembodiments of FIGS. 5A and 5B and FIGS. 6A and 6B do not lose anyaccuracy at lower speeds, although less accuracy may be achieved athigher speeds by the embodiment of FIGS. 6A and 6B as compared with theembodiment of FIGS. 5A and 5B.

The above embodiments use scaling factors of two, four and sixteen. Theinvention is not limited to these specific scaling factors. Otherscaling factors may also be used.

In the above embodiments, the comparator may include processor 14 andinstructions in ROM and/or RAM for comparing XCount or YCount to thevalues mentioned above. Further, scaler 22 may include processor 14 andinstructions in ROM and/or RAM for scaling, or dividing XCount or YCountby the values mentioned above. Although the above embodiments, asdescribed, represent a signed displacement and scaling factor,respectively, in mantissa and exponent bit fields (a floating pointformat), these values may be represented, and the scaling may beperformed, in various other ways known in the art. In addition to asoftware or firmware implementation of the invention, the invention mayalso be implemented in hardware.

The present invention has been described in terms of preferred andexemplary embodiments thereof. Numerous other embodiments, modificationsand variations within the scope and spirit of the appended claims willoccur to persons of ordinary skill in the art from a review of thisdisclosure. In the claims, the use of the labels for algorithm variablesappearing in the specification is for convenience and clarity and is notintended to have any limiting effect.

I claim:
 1. A pointing device comprising: a tracking engine configured to track a movement amount of an operation instrumentality of the pointing device in a first direction and to indicate the movement amount as a first value; determining means configured to examine the first value to determine whether scaling of the first value should be performed based on the first value and to determine whether scaling of the first value should be performed based on whether the first value can be represented by a first predetermined number of bits; and a scaler configured to scale the first value by a first scaling factor when the determining means determines that scaling is to be performed and to scale the first value when the determining means determines that the first value cannot be represented by the first predetermined number of bits, the scaler being configured to scale the first value by the first scaling factor, and to set the first scaling indicator to indicate that the first value has been scaled by the first scaling factor; and a position reporter configured to report information including the first value if no scaling has been performed, and in the event scaling has been performed, to report the scaled first value and a first scaling indicator corresponding to the first scaling factor.
 2. The pointing device of claim 1, wherein: the tracking engine is further configured to track a movement amount of an operation instrumentality of the pointing device in a second direction, and to indicate the movement amount as a second value; the determining means is further configured to determine whether scaling of the second value should be performed based on whether the second value can be represented by a second predetermined number of bits, the scaler is configured to scale the second value when the determining means determines that the first value cannot be represented by the second predetermined number of bits, the scaler being configured to scale the second value by a second scaling factor, and to set a second scaling indicator to indicate that the first value has been scaled by the second scaling factor, and the information that the position reporter is configured to report includes the second value and the second scaling indicator.
 3. The pointing device of claim 1, wherein: the determining means is configured to determine whether a magnitude of the first value is within a predetermined range, and the scaler is configured to scale the first value when the determining means determines that the first value is outside the predetermined range.
 4. The pointing device of claim 1, wherein: the tracking engine is further configured to track a movement amount of an operation instrumentality of the pointing device in a second direction and to indicate the movement amount as a second value, the determining means is further configured to examine the second value to determine whether scaling of the second value should be performed based on the second value, the scaler is further configured to scale the second value by a second scaling factor when the determining means determines that scaling is to be performed, and the position reporter is further configured to report information including the second value if no scaling has been performed, and in the event scaling has been performed, to report the scaled second value and a second scaling indicator corresponding to the second scaling factor.
 5. The pointing device of claim 4, wherein: the determining means is configured to determine whether a magnitude of the second value is within the predetermined range, and the scaler is configured to scale the second value when the determining means determines that the magnitude of the second value is outside the predetermined range.
 6. The pointing device of claim 1, wherein the pointing device is a wireless pointing device.
 7. The pointing device of claim 6, wherein the wireless pointing device is an optically tracking wireless pointing device.
 8. The pointing device of claim 1, wherein: the determining means is configured to determine whether scaling should be performed, and to select a first scaling factor from among a plurality of scaling factors, based on a magnitude of the first value.
 9. The pointing device of claim 8, wherein: the tracking engine is further configured to track a movement amount of an operation instrumentality of the pointing device in a second direction and to indicate the movement amount as a second value, the determining means is further configured to examine the second value to determine whether scaling of the second value should be performed based on the second value and to select a second scaling factor from among the plurality of scaling factors, based on a magnitude of the second value, the scaler is further configured to scale the second value by the second scaling factor when the determining means determines that scaling of the second value is to be performed, and the position reporter is further configured to report information including the second value if no scaling has been performed, and in the event scaling has been performed, to report the scaled second value and a second scaling indicator corresponding to the second scaling factor.
 10. A pointing device comprising: a tracking engine configured to track a movement amount of an operation instrumentality of the pointing device in a first direction and to indicate the movement amount as a first value; a scaler; and determining means for determining whether the first value can be represented by a first predetermined number of bits, and when the determining means determines that the first value can be represented by the first predetermined number of bits, setting a first scaling indicator to indicate that the first value is unscaled; when the first value cannot be represented by the first predetermined number of bits, the determining means determines whether the first value can be represented by a second predetermined number of bits, which is different from the first predetermined number of bits, and when the first value can be represented by the second predetermined number of bits, the scaler is configured to scale the first value by a first scaling factor, and to set a first scaling indicator to indicate that the first value is scaled by the first scaling factor; and when the determining means determines that the first value cannot be represented by the second predetermined number of bits, the determining means determines whether the first value can be represented by a third predetermined number of bits, which is different from the first and the second predetermined number of bits, and when the first value can be represented by the third predetermined number of bits, the scaler is configured to scale the first value by a second scaling factor, and to set the first scaling indicator to indicate that the first value is scaled by the second scaling factor; and a position reporter configured to report information including the first value if no scaling has been performed, and in the event scaling has been performed, outputting the scaled first value and the first scaling indicator.
 11. The pointing device of claim 10, wherein the determining means determines that the first value cannot be represented by the third predetermined number of bits the scaler is configured to scale the first value by a third scaling factor, and to set the first scaling indicator to indicate that the first value is scaled by the third scaling factor.
 12. The pointing device of claim wherein: the tracking engine is further configured to track a movement amount of an operation instrumentality of the pointing device in a second direction and to indicate the movement amount as a second value, the determining means is further for determining whether the second value can be represented by the first predetermined number of bits and when the determining means determines that the second value can be represented by the first predetermined number of bits, setting a second scaling indicator to indicate that the second value is unscaled, when the second value cannot be represented by the first predetermined number of bits, the determining means is further for determining whether the second value can be represented by the second predetermined number of bits, and when the second value can be represented by the second predetermined number of bits, the scaler is configured to scale the second value by the first scaling factor, and to set a second scaling indicator to indicate that the second value is scaled by the first scaling factor; and when the determining means determines that the second value cannot be represented by the second predetermined number of bits, the determining means is for determining whether the second value can be represented by the third predetermined number of bits, and when the second value can be represented by the third predetermined number of bits, the scaler is configured to scale the second value by the second scaling factor, and to set the second scaling indicator to indicate that the second value is scaled by the second scaling factor; and the position reporter is further configured to reporting information including the second value if no scaling of the second value has been performed, and in the event scaling of the second value has been performed, outputting the scaled second value and the second scaling indicator.
 13. The pointing device of claim 12, wherein when the determining means determines that the second value cannot be represented by the third predetermined number of bits, the scaler is configured to scale the second value by a third scaling factor, and to set the second scaling indicator to indicate that the second value is scaled by the third scaling factor.
 14. A pointing device, comprising: a tracking engine configured to track a movement amount of an operation instrumentality of the pointing device in a first direction and to indicate the movement amount as a first value; determining means configured to determine the smallest of first, second and third ranges of values into which the first value falls, and to set a first scaling indicator to indicate scaling by a first selected scaling factor based on the determined range if the first value falls into one of the first, the second and the third ranges; a scaler configured to scale the first value by the first selected scaling factor; and a position reporter configured to report information including the first value if no scaling has been performed, and in the event scaling has been performed, to report the scaled first value and the first scaling indicator.
 15. The pointing device of claim 14, wherein: the tracking engine is further configured to track a movement amount of an operation instrumentality of the pointing device in a second direction and to indicate the movement amount as a second value, the determining means is further configured to determine the smallest of the first, the second and the third ranges of values into which the second value falls, and to set a second scaling indicator to indicate scaling by a second selected scaling factor based on the determined range if the second value falls into one of the first, the second and the third ranges, the scaler is further configured to scale the second value by the second selected scaling factor, and the position reporter is further configured to report information including the second value if no scaling of the second value has been performed, and in the event scaling of the second value has been performed, to report the scaled second value and the second scaling indicator.
 16. The pointing device of claim 1, wherein the determining means comprises circuitry that compares the first value with predetermined range boundary values.
 17. The pointing device of claim 1, wherein the determining means comprises: a memory that contains computer-readable instructions; and a processor that executes the computer-readable instructions, wherein the processor compares the first value with predetermined range boundary values.
 18. The pointing device of claim 1, wherein the position reporter comprises a wireless transmitter that sends a reporting packet over a wireless communications channel, the reporting packet containing movement information regarding the pointing device.
 19. The pointing device of claim 18, wherein the position reporter inserts a first field and a second field in the reporting packet, wherein the first field is indicative of the first value and the second field contains a scaling flag, and wherein the scaling flag is indicative whether the first scaling factor has been applied to the first value. 